Request and Response Cycle in ASP.Net AJAX

The difference between how a traditional web application model and an Ajax-based web application model works. In traditional web applications, when a form is submitted, a request is sent to the web server. The web server acts upon this and sends back the response in the form of a web page. In this process, a lot of bandwidth is consumed, as the entire page has to be submitted, and either the same page or a new page has to be sent back as a response. More often than not, during this postback, much of the HTML of the first page is present in the second page. This is the case for every user interaction that happens on the client browser. The result is higher response times from the server, which thus affect the overall performance and create a rich user experience.

On the other hand, when an Ajax-based web application sends requests to the web server, the web server in return sends only the data that is requested. This is usually done in SOAP, HTML, XML, plain text, or JSON, and using JavaScript on the client to process the response. In this process, the amount of data interchange between the server and client is greatly reduced, thus improving the responsiveness of the application. This enhances rich user experience as the web server saves a lot of time by processing only the data that is required.